The effects of nifedipine on blood pressure (BP), left ventricular hypertrophy, and diastolic function were evaluated in 14 patients with essential hypertension (EH). All males with a mean age of 44 +/- 6 years (range 35-58 years), and in ten normotensive subjects (control group) aged 32-42 years (mean age 36 +/- 4). A complete echocardiogram (ECHO) was performed in basal conditions after 1 and 6 months of therapy with nifedipine (20-40 mg/day). Left ventricular echocardiograms (LV ECHO, M-mode, two-dimensional guided) were plotted with a simultaneous ECG tracing by means of a computerized system that allows evaluation of the following parameters: LV end-diastolic and systolic diameters (EDD, ESD); variations in LV diameter and volume during the entire cardiac cycle, and the velocities of such variations; end-diastolic thicknesses of the interventricular septum and posterior wall (ST, PWT); LV mass, mass/volume (M/V) index, end-diastolic diameter/thickness (D/Th) index, and LV ejection fraction (EF). Left ventricular volume curves were obtained and the contributions of rapid filling (RF) and atrial systole (AS) to EDV were evaluated. Filling velocities during RF (vRF) and AS (vAS) were estimated, as well as the isovolumic relaxation period (IR). No significant changes were observed in the heart rate. After 1 month of therapy, systolic and diastolic BP were significantly decreased (p less than 0.05). ST and PWT were reduced, with a simultaneous increase in EDD and EDV (p less than 0.01). LV mass was slightly reduced, as was the M/V index. The D/Th index was increased (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)